Cytogenetics played an essential role in studies of chromosome structure, behavior, and evolution in numerous plant species. The advent of molecular cytogenetics combined with recent development of genomic resources has ushered in a new era of chromosome studies that have greatly advanced our knowledge of karyotypic diversity, genome and chromosome organization, and chromosomal evolution in legumes. This review summarizes some of the achievements of cytogenetic studies in legumes in the Phaseoloid clade, which includes several important legume crops such as common bean (Phaseolus, and pigeonpea [Cajanus cajan (L.) Huth]. In the Phaseoloid clade, karyotypes are mostly stable. There are, however, several species with extensive chromosomal changes. Fluorescence in situ hybridization has been useful to reveal chromosomal structure by physically mapping transposons, satellite repeats, ribosomal DNA genes, and bacterial artificial chromosome clones onto chromosomes. Polytene chromosomes, which are much longer than the mitotic chromosomes, have been successfully found and used in cytogenetic studies in some Phaseolus and Vigna species. Molecular cytogenetics will continue to be an important tool in legume genetics and genomics, and we discuss future applications of molecular cytogenetics to better understand chromosome and genome structure and evolution in legumes.

Introduction Branchio-oto-renal (BOR) syndrome is an autosomal dominant genetic disorder characterized by second branchial arch anomalies, hearing impairment, and renal malformations. Pathogenic mutations have been discovered in several genes such as EYA1, SIX5, and SIX1. However, nearly half of those affected reveal no pathogenic variant by traditional genetic testing. Methods and materials Whole Exome sequencing and/or Sanger sequencing performed in 10 unrelated families from Turkey, Iran, Ecuador, and USA with BOR syndrome in this study. Results We identified causative DNA variants in six families including novel c.525delT, c.979T>C, and c.1768delG and a previously reported c.1779A>T variants in EYA1. Two large heterozygous deletions involving EYA1 were detected in additional two families. Whole exome sequencing did not reveal a causative variant in the remaining four families. Conclusions A variety of DNA changes including large deletions underlie BOR syndrome in different populations, which can be detected with comprehensive genetic testing.